How this is calculated
- This calculator applies one assumed average annual inflation rate β the number you enter β compounded every year, both into the past and into the future, to work out an equivalent amount with the same purchasing power.
- It does not use official historical price-index data for any specific year. It's a simplified, symmetric model: past value = base Γ· (1 + rate)years, future value = base Γ (1 + rate)years.
- The default rate shown is a commonly cited long-run average inflation figure for the US, meant purely as a reasonable starting example β feel free to change it to model a different scenario.
Range shown
From 1 to 10 years before/after the base year, values are shown in 1-year steps; beyond 10 years, they're shown in 5-year steps, up to 50 years before and after.
Important notes
Both the past and future values here are assumption-based estimates built on the single rate you enter, not a record of actual historical prices or a forecast of real future inflation. This calculator does not provide investment or financial advice β please consult a professional for any important financial decisions involving asset allocation or investing.
Frequently Asked Questions
Why does the past value come out lower than the base amount?
Because prices generally rise over time, it took less money in the past to have the same purchasing power as today's base amount. For example, today's $10,000 could buy noticeably more than $10,000 would have bought several decades ago β so the "equivalent" past amount is smaller.
Does changing the assumed rate make a big difference?
Yes β because the rate compounds every year, even a small change in the assumed rate has a much bigger effect the further out you go. Try a few different rates to compare scenarios.
Is this the same as investment returns?
No. This calculator only models the change in purchasing power due to inflation. It's unrelated to the actual returns on savings, stocks, real estate, or any other asset, and isn't investment advice.